Osg 1067300 Straight Flute Tap 5-40 Unc Bottoming Hss

Product Description

The OSG 1067300 is a straight flute tap designed to cut 5-40 UNC internal threads in a wide range of ferrous and non-ferrous metals. It features a bottoming chamfer, which starts the thread cut very close to the bottom of a blind hole, making it the correct choice when full threads are required through nearly the entire depth of a bore. Built from high-speed steel with a bright, uncoated finish, it delivers dependable performance in general-purpose tapping applications. The tap carries an H2 thread limit and a 2B/3B class of fit, meeting standard tolerance requirements for most machine thread assemblies. Overall length is 1-15/16 inches with a 5/8-inch thread length.

This tap is suited for hand tapping and machine tapping operations in job shops, production environments, and maintenance settings. It is commonly used when threading blind holes in aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel workpieces. The two-flute straight-flute geometry provides chip clearance in through-hole applications and controlled cutting action in shallow blind bores. Machinists, tool and die workers, and maintenance technicians regularly reach for this configuration when bottoming thread depth is critical to part function.

Key Features

• Bottoming chamfer for threading close to the bottom of blind holes
• 2 straight flutes for chip clearance and cutting stability
• H2 thread limit with 2B/3B class of fit for standard tolerance assemblies
• High-speed steel construction for durability across a broad range of workpiece materials
• Bright/uncoated finish suitable for general-purpose use without added coating cost
• Right-hand thread direction, standard for most fastener applications

Compatibility

Designed for tapping 5-40 UNC threads in aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel. Part of OSG Series 104.

Installation Notes

This tap is installed by machinists and maintenance technicians using a tap wrench, tapping head, or CNC rigid-tap cycle. Before tapping, ensure the workpiece is secured and the pilot hole diameter matches the recommended drill size for 5-40 UNC threads. Apply an appropriate cutting fluid for the workpiece material to extend tool life and improve thread finish. When bottoming in a blind hole, advance carefully to avoid breaking the tap against the bottom of the bore.